Abstract
A diffusion equation is used to predict the sound propagation in
long rooms with diffusely reflecting boundaries. The model is
defined by two parameters, the coefficient of diffusion depending
on the mean free path, and an exchange coefficient expressing wall
absorption. The diffusion equation is solved for time-varying
sources and in stationary state. Analytical expressions of the
sound attenuation and reverberation in infinite, semi-infinite and
finite long rooms are quite in accordance with numerical
simulations of diffuse sound field. It is also shown that the
diffusion model allows to predict experimental observations: the
decay curves are not linear, the reverberation time increases with
the source-receiver distance, and sound attenuation is linear
along corridors. The dependence of the coefficient of diffusion
with the degree of wall diffusion is also discussed.
Original language | English |
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Journal | Applied Acoustics |
Volume | 56 |
Issue number | 4 |
Pages (from-to) | 217-240 |
ISSN | 0003-682X |
DOIs | |
Publication status | Published - 1999 |